Absolute velocity measuring device

• US 20070090991A1
• Filed: 05/31/2006
• Published: 04/26/2007
• Est. Priority Date: 05/31/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nagasaku, Toshiyuki, Kuroda, Hiroshi, Yoshikawa, Tokuji, Kuragaki, Satoru
• Application Number:
  US11/443,195
• Publication Number:
  US 20070090991A1
• Time in Patent Office: Days
• US Class Current: 342/70
• CPC Class Codes: G01S 13/589 measuring the velocity vector
• CPC Class Codes: G01S 13/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track G01S13/64 takes precedence
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems

Abstract

In a configuration of a technique in the related art, since two Doppler sensors are used to measure velocity in two directions, and a set of transmission circuit and reception circuit are provided for each of directions to be measured, a device becomes large and expensive. Moreover, in the related art, since signal processing is performed by using output of each of the two Doppler sensors, axis adjustment in each of emission directions of the two Doppler sensors needs to be performed separately, therefore there is a difficulty that appropriate axis adjustment is complicated and difficult. An absolute velocity measuring device is mounted in a vehicle, and includes a transceiver for transmitting and receiving a wave, a transmission-wave branch section that branches a unidirectional wave transmitted from the transceiver in a plurality of directions, and converges reflected waves of waves branched in the plurality of directions from the ground into the unidirectional wave to be received by the transceiver, and a signal processing section that obtains a signal based on a reflected wave that has been received from the transceiver, and processes the obtained signal and thus calculates a plurality of kinds of behavioral information of the vehicle, and then outputs the relevant behavioral information.

Claims

1. An absolute velocity measuring device comprising:

a transceiver for transmitting and receiving a wave, and being mounted in a vehicle;

a transmission-wave branch section for branching a unidirectional wave transmitted from said transceiver in a plurality of directions, and converging reflected waves from the ground for the waves branched in the plurality of directions into the unidirectional wave to be received by said transceiver; and

a signal processing section for obtaining a signal based on the reflected wave which is received from said transceiver, and processing an obtained signal and calculating a plurality of kinds of behavioral information of the vehicle, and then outputting the relevant behavioral information.

2. The absolute velocity measuring device according to claim 1,

wherein said transceiver outputs a Doppler signal containing Doppler shift information based on the reflected wave which is received to said signal processing section.

3. The absolute velocity measuring device according to claim 2,

wherein said signal processing section calculates velocity in each of transmission direction components of a wave based on a result of performing Fourier Transform to the Doppler signal.

4. The absolute velocity measuring device according to claim 3,

wherein said signal processing section sets each of the transmission direction components based on the result of Fourier Transform to velocity of the relevant transmission direction component with intensity or a divergence range of a signal.

5. The absolute velocity measuring device according to claim 3,

wherein said signal processing section carries out moving average of the result of performing the Fourier Transform with a frequency axis, and calculates velocity of the transmission direction component based on a result of the moving average.

6. The absolute velocity measuring device according to claim 1,

wherein the plurality of kinds of behavioral information include velocity in a back and forth direction, velocity in a left and right direction, magnitude of velocity, a moving direction, a pitch angle, and a roll angle of the vehicle.

7. The absolute velocity measuring device according to claim 1,

wherein said transceiver has a transmission-wave switching function for switching a wave in a plurality of directions in a time-shared manner.

8. The absolute velocity measuring device according to claim 1,

wherein, in said transmission-wave branch section, at least one of intensity and a divergence range of the wave is varied depending on a branch direction of the wave.

9. The absolute velocity measuring device according to claim 1,

wherein said transmission-wave branch section includes a region that transmits the wave and a region that does not transmit the wave.

10. The absolute velocity measuring device according to claim 1,

wherein said transmission-wave branch section includes a lens.

11. An absolute velocity measuring device comprising:

a transceiver for transmitting and receiving a wave, and being fixed to a vehicle in a way that an antenna surface is directed to the front of a vehicle;

a transmission-wave branch section for, on a plane defined by an axis in a left and right direction of the antenna surface and a vertical axis perpendicular to the antenna surface, branching a wave transmitted from said transceiver in a plurality of directions making predetermined angles in left and right with respect to the vertical axis respectively, and converging reflected waves from the ground for the branched waves in the plurality of directions into the unidirectional wave to be received by said transceiver; and

a signal processing section for obtaining a Doppler signal containing Doppler shift information based on a reflected wave which is received by said transceiver, and calculating velocity in a back and forth direction, velocity in a left and right direction, magnitude of velocity, and a moving direction of the vehicle from each of transmission direction components obtained based on a result of performing Fourier Transform to the Doppler signal.

12. An absolute velocity measuring device comprising;

;

a transceiver for transmitting and receiving a wave, and being fixed to a vehicle in a way that an antenna surface is directed to a travelling direction of a vehicle;

a transmission-wave branch section for, on a plane defined by an axis in an up and down direction of the antenna surface and a vertical axis perpendicular to the antenna surface, branching a wave transmitted from said transceiver in a plurality of directions making predetermined angles vertically with respect to the vertical axis respectively, and converging reflected waves from the ground with respect to the branched waves in the plurality of directions into the unidirectional wave to be received by said transceiver; and

a signal processing section for obtaining a Doppler signal containing Doppler shift information based on a reflected wave which is received from said transceiver, and calculating velocity in a back and forth direction and a pitch angle of the vehicle from each of transmission direction components obtained based on a result of performing Fourier Transform to the Doppler signal.